1. Field of the Invention
The present invention relates to an improved suspension for a coulter wheel assembly of the type primarily intended for attachment to a tractor and use in combination therewith for applying agricultural chemicals, preferably in a granular form, though the invention is not limited thereto. The invention is characterized by the suspension frame for the coulter wheel assembly including a back angle pivot for the double disc openers and the following press wheels. By virtue of the pivoting support arms and the back angle pivot attachment of the coulter wheel means, the entire assembly will track properly behind the tractor, regardless of changes of direction made by the tractor. The invention is further characterized by its provision of depth adjustment means whereby the double disc openers of the assembly may be easily and efficiently adjusted for depth of cut so as not to disturb shallow roots of the crop being treated.
2. Description of the Prior Art
Within the agricultural industry, it is well known to use double disc openers for the purpose of creating a furrow in the soil so that agricultural chemicals, and even seeds, may be placed within the furrow. It is also known to follow the double disc openers with what is commonly referred to as a press wheel for the purpose of closing the furrow once material has been deposited therein. Such devices are typically assembled as a gang of double disc openers and following wheels which are typically hitched to and towed behind a tractor. Examples of such prior art devices are known in the patent literature and are illustrated and described in U.S. Pat. No. 522,329 to Packham; U.S. Pat. No. 537,261, to Avery; U.S. Pat. No. 3,348,505, to Smith; U.S. Pat. No. 3,658,018, to Connor; U.S. Pat. No. 4,377,979, to Peterson, et al.; and U.S. Pat. No. 4,926,767, to Thomas.
In this prior art and, in particular the patents to Packham and Peterson, it can be seen that means are provided for adjusting the depth of the furrow made by the device. However, in all of these prior art devices, the suspension means for the coulter wheels is such that when the tractor makes a sharp turn, the double disc openers tend to slide to one side, not tracking properly and not cutting a proper depth of furrow. This condition is particularly aggravated in the prior art devices which also employ a following press wheel.
It is, therefore, clear that there remains a need in the art for an improved suspension for such coulter wheel assemblies whereby the double disc openers and following press wheels will not only track properly when the towing implement makes sharp turns, as are often necessary in agricultural environments, but also which provides for a virtually constant depth of furrow so that the material being deposited is accurately, efficiently, and economically applied.